Organic and conventional farming systems shape soil bacterial community composition in tropical arable farming

Soils present a limited resource for agricultural production and bear a vast diversity of organisms crucial for crop health and the provision of ecosystem services. There is growing evidence that agricultural practices affect soil microbial community structure and function but currently, there is a knowledge gap when it comes to tropical arable farming systems. In this study, we investigated the long-term impact of organic and conventional production systems on bacterial communities in two field trial located on a rhodic and humic nitisol in the Central Highlands of Kenya. The field sites operate on a full factorial design, testing farming systems (organic vs conventional) and input levels (high vs low). Including four field replication we assessed soil bacterial community structure via amplicon sequencing of the 16S rRNA gene and soils capacity for nitrification and nitrous oxide reduction via qPCR of functional genes (bacterial and archaeal amoA, nosZ) after 12 years of distinct management and before the start of the 5th three-year crop rotation period in 2019. The abundances of amoA bearing nitrifiers and nosZ bearing nitrous oxide reducers were enhanced in the high input organic production system on humic but not in rhodic nitisols. For both soil types, high input organic production system resulted in distinct bacterial community structure with enhanced bacterial richness compared to conventional and low input production systems. In rhodic and humic nitisols 160 and 84 OTUs were found to be indicative for organic production system at high input levels organic. Taxa associated with this system were identified as potential primary decomposers or symbionts related to plant nitrogen fixation, suggesting organic fertilization strategies such as manure composting as major driver for changes in soil bacterial community structure. This study reveals that organic production systems at high input levels on tropical nitisols translates to distinct soil bacterial communities with increased capacity for soil processes that are crucial for crop nutrient supply

A Framework for city leadership in multilevel governance settings: the comparative contexts of Italy and the UK

This paper discusses the role of city leadership in the current multilevel governance settings and provides a conceptual framework for understanding the main elements of city leadership. Forms of political, managerial and civic leadership have been distinguished within city leadership and the main actors, structures, processes and followership patterns are examined using Italy and the UK as starting points of comparison. This comparative framework sheds a light on some common and different features in the city leadership patterns in Italy and the UK, such as the cross-cutting and multilayered administrative context for public service delivery; the common trend towards strengthening the executive side of political leadership rather than the representative one; the growing relevance of forms of civic leadership as a trigger for creating public and social value and for enhancing the resilience of the territories. Main differences deal instead with the role of central government in defining the role of city leaders, where Italy seems to experience a return towards greater centralization and controls, and the UK is experiencing an opposite trend towards the empowerment of local communities. Finally, the paper sets out some future directions for the research agenda on city leadership we are seeking to pursue

Reversal of economic fortunes: institutions and the changing ascendancy of Barcelona and Madrid as economic hubs

This paper looks at the divergent economic trajectories of Barcelona and Madrid since Spain's transition to democracy. It highlights how Barcelona, the city that was better positioned four decades ago to emerge as the main Spanish economic hub, has lost out to Madrid. We argue that the contrasting trajectories of the two cities have less to do with the pull of Madrid as the capital of Spain, with the development of new infrastructure in the country, or with agglomeration economies, and more with institutional factors. A growing societal divide in Barcelona along economic, social, and identity lines has led to a greater breakdown of trust and to the development of strong groups with limited capacity to bridge with one another than in Madrid. This has entailed the emergence of negative externalities that have limited the economic potential for growth in Barcelona and facilitated the rise of Madrid as the main economic hub within Spain